Unitarily formed expandable spinal implant and method of manufafturing and implanting same

ABSTRACT

A unitarily formed expandable spinal implant for insertion in a disc space between two adjacent vertebrae. The unitarily formed expandable spinal implant is moveable from an unexpanded configuration to an expanded configuration, and can be manufactured by a 3-dimensional printer. The unitarily formed expandable spinal implant includes an upper portion, a lower portion, a proximal wall, a first distal wall portion, a second distal wall portion, and a separator connected by at least one point of attachment to the spinal implant. A separation tool breaks the separator free from the at least one point of attachment, and moves the separator within the implant to force expansion thereof from the unexpanded configuration to the expanded configuration.

The present application is a divisional of U.S. application Ser. No.14/602,036 filed Jan. 21, 2015; all of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

The present invention relates to a unitarily formed expandable spinalimplant for use in spinal surgery. More particularly, the presentinvention relates to a unitarily formed expandable spinal implant forimplantation into a disc space between two adjacent vertebrae, andmovable from an unexpanded configuration to an expanded configuration.More specifically, the present invention relates to a unitarily formedexpandable spinal implant including a component fixed as a unitary partthereof, which is configured, following implantation of the implant intoa disc space between two adjacent vertebrae, to be broken free by aninsertion tool, and moved within the implant to force expansion of theimplant. The present invention further relates to a unitarily formedexpandable spinal implant manufactured using a 3-dimensional printer.

DESCRIPTION OF THE RELATED ART

Expandable spinal implants are known in the art. Such expandable spinalimplants can be configured to ultimately have lordotic, taperedconfigurations to assist in the restoration or enhancement of spinallordosis. The expandability of such implants allows placement thereofinto a corresponding surgically-enhanced disc space between two adjacentvertebrae through a relatively small surgical opening in a patient'sbody. Thereafter, expansion of the implants provides the advantage ofincreasing the heights thereof within the disc space to assist in therestoration or enhancement of spinal lordosis. The related artexpandable fusion implants, however, have certain disadvantages.

The related art implants are typically manufactured with multiple parts,using traditional manufacturing methods, requiring the use of anexcessive amount of material, e.g., titanium, to manufacture all of thecomponents. For example, a significant portion of extra manufacturingmaterial is milled away to configure the various necessary componentsthat define the implant. The need to remove such extra manufacturingmaterial both increases the manufacturing cost, and, for the sake ofefficiency, requires the manufacture of the various components of theimplants in bulk quantities.

The related art implants further are not unitarily formed expandablespinal implants configured to, after implantation into the disc space,be converted to multiple-part implants by breaking one part free fromthe remainder of the implant and expanding the implant with that onepart.

SUMMARY OF THE INVENTION

In accordance with the invention, a unitarily formed expandable spinalimplant is configured to be inserted into a disc space between twoadjacent vertebrae.

The unitarily formed expandable spinal implant includes an upper portionhaving a proximal end and an opposite distal end, an upper portionexterior surface and an upper portion interior surface, the upperportion exterior surface and the upper portion interior surfaceextending from at least adjacent the proximal end to at least adjacentthe distal end of the upper portion, the upper portion exterior surfaceconfigured to contact one of the two adjacent vertebrae, the upperportion interior surface at least in part declining between the upperportion proximal end and the upper portion distal end, and at least oneopening being provided in the upper portion between the upper portioninterior surface and the upper portion exterior surface.

The unitarily formed expandable spinal implant includes a lower portionhaving a proximal end and an opposite distal end, a lower portionexterior surface and a lower portion interior surface, the lower portionexterior surface and the lower portion interior surface extending fromat least adjacent the proximal end to at least adjacent the distal endof the lower portion, the lower portion exterior surface configured tocontact the other of the two adjacent vertebrae, the lower portioninterior surface at least in part declining between the lower portionproximal end and the lower portion distal end, and at least one openingbeing provided in the lower portion between the lower portion interiorsurface and the lower portion exterior surface.

The unitarily formed expandable spinal implant further includes achamber between portions of the upper portion and the lower portion.

The unitarily formed expandable spinal implant further includes aproximal wall having an exterior surface and an interior surface, theproximal wall extending between the upper portion and the lower portion,the proximal wall having a maximum height, and an aperture provided inthe proximal wall between the interior surface and the exterior surfacethereof, the aperture provided in the proximal wall communicating withthe chamber.

The unitarily formed expandable spinal implant further includes a firstdistal wall portion and a second distal wall portion, the first distalwall portion being attached to the upper portion at the distal endthereof, the second distal wall portion being attached to the lowerportion at the distal end thereof, the first distal wall portion and thesecond distal wall portion having a first height less than the maximumheight of the proximal wall.

The unitarily formed expandable spinal implant further includes aseparator having a leading portion, the separator being unitarily formedwith one of the upper portion interior surface, the lower portioninterior surface, and the interior surface of the proximal wall. Theseparator is configured to be separated by an insertion tool insertedthrough the aperture in the proximal wall and into contact with atrailing portion of the separator from at least one point of attachmentto the remainder of the spinal implant, thereby converting the implantinto a multiple-part implant. The insertion tool is further configuredto force the separator toward the distal end of the spinal implant, and,in doing so, force the upper portion and the lower portion apart fromone another to expand the spinal implant in the disc space into anexpanded configuration, the first distal wall portion and the seconddistal wall portion having a second height in the expanded configurationgreater than the maximum height of the proximal wall.

In accordance with another aspect of the present invention, a method ofmanufacturing a unitarily formed expandable spinal implant forimplantation in a disc space between two adjacent vertebrae is provided.The method includes utilizing a 3-dimensional printer to lay downsequential layers of an upper portion having a proximal end and anopposite distal end, the upper portion having an upper portion exteriorsurface and an upper portion interior surface, the upper portionexterior surface and the upper portion interior surface extending fromat least adjacent the upper portion proximal end to at least adjacentthe upper portion distal end, the upper portion exterior surface beingconfigured to contact one of the two adjacent vertebrae, the upperportion interior surface at least in part declining between the upperportion proximal end and the upper portion distal end, and at least oneopening being defined between the upper portion interior surface and theupper portion exterior surface; utilizing the 3-dimensional printer tolay down sequential layers of a lower portion having a proximal end andan opposite distal end, the lower portion having a lower portionexterior surface and a lower portion interior surface, the lower portionexterior surface and the lower portion interior surface extending fromat least adjacent the lower portion proximal end to at least adjacentthe lower portion distal end, the lower portion exterior surface beingconfigured to contact the other of the two adjacent vertebrae, the lowerportion interior surface at least in part inclining between the lowerportion proximal end and the lower portion distal end, and at least oneopening being defined between the lower portion interior surface and thelower portion exterior surface; utilizing the 3-dimensional printer tolay down sequential layers of a proximal wall having an exterior surfaceand an interior surface, the proximal wall extending between the upperportion and the lower portion, the proximal wall having a maximumheight, and an aperture provided in the proximal wall between theinterior surface and the exterior surface thereof, the aperture providedin the proximal wall communicating with a chamber formed betweenportions of the upper portion interior surface and the lower portioninterior surface; utilizing the 3-dimensional printer to lay downsequential layers of a first distal wall portion and a second distalwall portion, the first distal wall portion being attached to the upperportion at the distal end thereof, the second distal wall portion beingattached to the lower portion at the distal end thereof, the firstdistal wall portion and the second distal wall portion having a firstheight less than the maximum height of the proximal wall; and utilizingthe 3-dimensional printer to lay down sequential layers of a separatorincluding a leading portion, the separator being unitarily formed withone of the upper portion interior surface, the lower portion interiorsurface, and the interior surface of the proximal wall by at least onepoint of attachment; wherein the separator is configured to be separatedfrom the at least one point of attachment, and be moved along at least aportion of the lower portion interior surface and at least a portion ofthe upper portion interior surface toward the first distal wall portionand the second distal wall portion to move the upper portion and thelower portion apart from one another into an expanded configuration, thefirst distal wall portion and the second distal wall portion having asecond height in the expanded configuration greater than the maximumheight of the proximal wall.

In accordance with yet another aspect of the present invention, a methodof implanting a unitarily formed expandable spinal implant into a discspace between two adjacent vertebrae is provided. The method includesutilizing the unitarily formed expandable spinal implant including: anupper portion having a proximal end, an opposite distal end, an upperportion exterior surface, and an upper portion interior surface, theupper portion exterior surface and the upper portion interior surfaceextending from at least adjacent the upper portion proximal end to atleast adjacent the upper portion distal end, the upper portion exteriorsurface being configured to contact one of the two adjacent vertebrae,the upper portion interior surface at least in part declining betweenthe upper portion proximal end and the upper portion distal end, and atleast one opening being defined between the upper portion interiorsurface and the upper portion exterior surface; a lower portion having aproximal end, an opposite distal end, a lower portion exterior surface,and a lower portion interior surface, the lower portion exterior surfaceand the lower portion interior surface extending from at least adjacentthe lower portion proximal end to at least adjacent the lower portiondistal end, the lower portion exterior surface being configured tocontact the other of the two adjacent vertebrae, the lower portioninterior surface at least in part declining between the lower portionproximal end and the lower portion distal end, and at least one openingbeing defined between the lower portion interior surface and the lowerportion exterior surface; a proximal wall having an exterior surface andan interior surface, the proximal wall extending between the upperportion and the lower portion, the proximal wall having a maximumheight, and an aperture provided in the proximal wall between theinterior surface and the exterior surface thereof; a chamber formedbetween portions of the upper portion interior surface, the lowerportion interior surface, and the interior surface of the proximal wall,the aperture formed in the proximal wall communicating with the chamber;a first distal wall portion and a second distal wall portion, the firstdistal wall portion being attached to the upper portion at the distalend thereof, the second distal wall portion being attached to the lowerportion at the distal end thereof, the first distal wall portion and thesecond distal wall portion having a first height less than the maximumheight of the proximal wall; and a separator including a leadingportion, the separator being unitarily formed with one of the upperportion interior surface, the lower portion interior surface, and theinterior surface of the proximal wall by at least one point ofattachment; wherein the separator is configured to be separated from theat least one point of attachment and be moved along at least a portionof the lower portion interior surface and at least a portion of theupper portion interior surface toward the first distal wall portion andthe second distal wall portion to move the upper portion and the lowerportion apart from one another into an expanded configuration, the firstdistal wall portion and the second distal wall portion having a secondheight in the expanded configuration greater than the maximum height ofthe proximal wall; inserting the spinal implant into the disc space;inserting an insertion tool through the aperture defined in the proximalwall and into contact with the separator; applying force to theseparator with the insertion tool to break the at least one point ofattachment; and forcing the separator along the upper portion interiorsurface and the lower portion interior surface toward the first distalwall portion and the second distal wall portion to move the upperportion and the lower portion apart from one another into the expandedconfiguration.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate preferred embodiments of theinvention and, together with the description, serve to explain theobjects, advantages, and principles of the invention. In the drawings:

FIG. 1 is a rear perspective view of a unitarily formed expandablespinal implant in accordance with the present invention in an unexpandedconfiguration;

FIG. 2 is a front perspective view of the unitarily formed expandablespinal implant of FIG. 1 in the unexpanded configuration;

FIG. 3 is a side elevational view of the unitarily formed expandablespinal implant of FIGS. 1 and 2 in the unexpanded configuration;

FIG. 4 is a perspective view of an insertion instrument configured toafford insertion of spinal implants in accordance with the presentinvention, the insertion instrument being depicted as having the spinalimplant of FIGS. 1-3 attached thereto;

FIG. 5 is a perspective view of a leading end of the insertioninstrument of FIG. 4 and a trailing end of the spinal implant of FIGS.1-3 showing the potential for insertion of the leading end of theinsertion instrument into the trailing end of the spinal implant;

FIG. 6 is a cross-sectional view along Line 6-6 of FIG. 4 of the spinalimplant of FIGS. 1-3 and the insertion instrument of FIG. 4 attached toone another;

FIG. 7 is a side cross-sectional view along Line 7-7 of FIG. 4 of thespinal implant of FIGS. 1-3 and the insertion instrument of FIG. 4attached to one another;

FIG. 8 is a side cross-sectional view enlarged from FIG. 7 showing thespinal implant of FIGS. 1-3 attached to the insertion instrument of FIG.4 prior to expansion of the spinal implant from the unexpandedconfiguration to an expanded configuration using the insertioninstrument to break a separator free from the remainder of the spinalimplant and move the separator inside the spinal implant to facilitateexpansion thereof;

FIG. 9 is a side cross-sectional view similar to FIG. 8 showing thespinal implant of FIGS. 1-3 attached to the insertion instrument of FIG.4 after expansion of the spinal implant into the expanded configurationusing the separator;

FIG. 10 is rear perspective view of another embodiment of a unitarilyformed expandable spinal implant in accordance with the presentinvention in an unexpanded configuration;

FIG. 11 is a front perspective view of the unitarily formed expandablespinal implant of FIG. 10 in the unexpanded configuration;

FIG. 12 is a side cross-sectional view of the spinal implant of FIGS. 10and 11 prior to expansion of the spinal implant from the unexpandedconfiguration to an expanded configuration using the insertioninstrument to break a separator free from the remainder of the spinalimplant and move the separator inside the spinal implant to facilitateexpansion thereof;

FIG. 13 is a side cross-sectional view similar to FIG. 12 showing thespinal implant of FIGS. 10 and 11 after expansion thereof into theexpanded configuration using the separator;

FIG. 14 is a rear perspective view of yet another embodiment of aunitarily formed expandable spinal implant in accordance with thepresent invention in an unexpanded configuration;

FIG. 15 is a front perspective view of the unitarily formed expandablespinal implant of FIG. 14 in the unexpanded configuration;

FIG. 16 is a side cross-sectional view of the spinal implant of FIGS. 14and 15 prior to expansion of the spinal implant from the unexpandedconfiguration to an expanded configuration using the insertioninstrument to break a separator free from the remainder of the spinalimplant and move the separator inside the spinal implant to facilitateexpansion thereof; and

FIG. 17 is a side cross-sectional view similar to FIG. 16 showing thespinal implant of FIGS. 14 and 15 after expansion thereof into theexpanded configuration using the separator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In accordance with the present invention, a first embodiment of aunitarily formed expandable spinal implant 10 is depicted in FIGS. 1-9.In accordance with the present invention, a second embodiment of aunitarily formed expandable spinal implant 110 is depicted in FIGS.10-13, and a third embodiment of a unitarily formed expandable spinalimplant 210 is depicted in FIGS. 14-17. As discussed below, each of thespinal implants 10, 110, and 210 are formed as a single part/component.Similar numerals are used to describe similar features of the unitarilyformed expandable spinal implants 10, 110, and 210.

The spinal implants 10, 110, and 210 can be used as fusion implants, andare configured for placement in a disc space between two adjacentvertebrae. The spinal implants 10, 110, and 210 can be packed withfusion promoting materials to facilitate their use as spinal fusioncages. To that end, the spinal implants 10, 110, and 210 includeinterior cavities (or chambers) C for receiving the fusion promotingmaterials therein. Furthermore, as discussed below, the spinal implants10, 110, and 210 can be moved from an unexpanded configuration to anexpanded configuration. In doing so, the implants 10, 110, and 210 canbe used in producing an angular relationship between the two adjacentvertebrae corresponding to naturally occurring physiologic lordosis.

As depicted in FIGS. 1-3, the spinal implant 10 includes a proximal end12 and a distal end 14 opposite from one another, and a mid-longitudinalaxis X-X extending through the proximal end 12 and the distal end 14.The spinal implant 10 includes an upper portion 20 having a proximal end22, a distal end 24 opposite the proximal end 22, an upper portionexterior surface 26, an upper portion interior surface 28, and aplurality of apertures 29 provided between the upper portion exteriorsurface 26 and the upper portion interior surface 28. Furthermore, thespinal implant 10 includes a lower portion 30 having a proximal end 32,a distal end 34 opposite the proximal end 32, a lower portion exteriorsurface 36, a lower portion interior surface 38, and a plurality ofapertures 39 provided between the lower portion exterior surface 36 andthe lower portion interior surface 38.

The upper portion interior surface 28 and the lower portion interiorsurface 38 in part define the interior cavity (or chamber) C of thespinal implant 10. As depicted in FIG. 3, the upper portion interiorsurface 28 declines from adjacent the proximal end 22 to adjacent thedistal end 24, and the lower portion interior surface 38 inclines fromadjacent the proximal end 32 to adjacent the distal end 34. The upperportion exterior surface 26 and the lower portion exterior surface 36can include surface roughenings 27 and 37, respectively. The surfaceroughenings 27 and 37 can be used to engage the adjacent vertebrae toinhibit movement of the spinal implant 10 after implantation thereof inthe disc space.

As depicted in FIG. 1, the spinal implant 10 includes a proximal wall 40at the proximal end 12 thereof. The proximal wall 40 extends between theupper portion 20 and the lower portion 30. The proximal wall 40 includesan upper edge portion 42 to which the proximal end 22 of the upperportion 20 is attached, and a lower edge portion 44 to which theproximal end 32 of the lower portion 30 is attached. The proximal wall40 also includes an exterior surface 46 and an interior surface 47. Theproximal wall 40 has a height H₁ (FIG. 8), and aperture 48 definedtherein positioned between the upper edge 42 and the lower edge 44. Theaperture 48 extends between the exterior surface 46 and the interiorsurface 47, and the interior surface 47 (with the upper portion interiorsurface 28 and the lower portion interior surface 38) in part define theinterior cavity C of the spinal implant 10.

The spinal implant 10, as depicted in FIG. 2, includes a first distalwall portion 50 and a second distal wall portion 52 at the distal end 14thereof. The first distal wall portion 50 is attached at the distal end24 of the upper portion 20, and the second distal wall portion 52 isattached at the distal end 34 of the lower portion 30. The first distalwall portion 50 depends downwardly from the upper portion 20, and thesecond distal wall portion 52 depends upwardly from the lower portion30. The second distal wall portion 52 includes side portions 54 and 55defining a notch 56 therebetween. The notch 56 is sized to receive thefirst distal wall portion 50 therein when the spinal implant 10 is inthe unexpanded configuration.

As depicted in FIG. 8, the first distal wall portion 50 and the seconddistal wall portion 52 together have a height H₂. The height H₂corresponds to the unexpanded configuration of the spinal implant 10.The height H₂ is less than the height H₁ of the proximal wall 40, andthus, the implant 10 has an overall tapered wedge profile in theunexpanded configuration thereof. The overall tapered wedge profilefacilitates insertion of the spinal implant 10 into the disc space.

The spinal implant 10 includes a separator 60 initially attached as aunitary part of the spinal implant 10. As depicted in FIG. 8, theseparator 60 is initially attached to the remainder of the spinalimplant 10 proximate the proximal wall 40. For example, the separator 60can be attached to one of the upper portion interior surface 28, thelower portion interior surface 38, and the interior surface 47 of theproximal wall 40. The separator 60 is attached to and suspended from theupper portion interior surface 28 of the upper portion 20 by at leastone stem. One or more stems 68 can be used for attachment to andsuspension from the upper portion interior surface 28, or alternativelyor in addition thereto, one or more stems 68 can be used for attachmentto and suspension of the separator 60 from the lower portion interiorsurface 38 and/or the interior surface 47 of the proximal wall 40.

As discussed below, the two stems 68 can be broken so that the separator60 can be separated from the upper portion interior surface 28.Thereafter, the separator 60 can be moved along the upper portioninterior surface 28 and the lower portion interior surface 38. Given theinclinations of the upper portion interior surface 28 and the lowerportion interior surface 38, movement of the separator 60 towards thedistal end 14 of the spinal implant 10 forces the upper portion 20 andlower portion 30 away from one another. In doing so, the spinal implant10 can be moved from the unexpanded configuration (FIG. 8) to anexpanded configuration (FIG. 9).

The separator 60 includes a trailing portion 62 and a leading portion64. The trailing portion 62 is positioned proximate the proximal wall40, and the leading portion 64 projects from upper and lower ends of thetrailing portion 62 toward the first distal wall portion 50 and thesecond distal wall portion 52. As depicted in FIG. 3, the trailingportion 62 is flattened, and the leading portion 64 is partiallycylindrical. Furthermore, the trailing portion 62 includes a threadedaperture 65 therein. Also as depicted in FIG. 3, an extension portion 66projects from the leading portion 64 toward the first distal wallportion 50 and the second distal wall portion 52. The present invention,however, is not limited to a separator 60 having the above-describedconfiguration. For example, the separators 160 and 260 used inassociation with the spinal implants 110 and 210, respectively, havedifferent configurations.

As depicted in FIGS. 1, 2, 3, 8, and 9, the upper portion 20 and thelower portion 30 further include a generally concave depression 70defined in the upper portion interior surface 28 and the lower portioninterior surface 38 proximate the first distal wall portion 50 and thesecond distal wall portion 52. The shape of the generally concavedepression 70 can be complementary to the shape of the leading portion64 of the separator 60. As such, receipt of the leading portion 64 inthe generally concave depression 70 can be used to inhibit furthermovement of the separator 60 toward the distal end 14 of the spinalimplant 10. Furthermore, receipt of the extension portion 66 in thenotch 56 between the side portions 54 and 55 of the second distal wallportion 52 can be used to inhibit side-to-side movement of the separator60 when the leading portion 64 is received in the generally concavedepression 70. Thus, the separator 60 can be moved toward the distal end14 to move the spinal implant 10 from the unexpanded configuration tothe expanded configuration, and ultimately be moved into seatingengagement in the generally concave depression 70 and the notch 56 tomaintain the spinal implant 10 in the expanded configuration.

As depicted in FIG. 9, the first distal wall portion 50 and the seconddistal wall portion 52 together have a height H₃. The height H₃corresponds to the expanded configuration of the spinal implant 10. Theheight H₃ is greater than the height H₁ of the proximal wall 40. Assuch, the spinal implant 10 can be inserted into the disc space havingan overall tapered wedge profile (unexpanded configuration), andthereafter the distal end 14 can be expanded from the height H₂ to theheight H₃ to produce an angular relationship between the two adjacentvertebrae corresponding to naturally occurring physiologic lordosis.

An insertion tool 80 is provided to facilitate insertion of the spinalimplant 10 into the disc space between the two adjacent vertebrae, andto facilitate expansion of the spinal implant 10 from the unexpandedconfiguration to the expanded configuration after insertion thereof.Furthermore, after implantation of the implant 10 into the disc space,the configuration of the insertion tool 80 affords breakage of theseparator 60 from the stems 68 (which attach the separator 60 to theimplant 10), and movement of the separator 60 along the upper portioninterior surface 28 and the lower portion interior surface 38 toward thedistal end 14 of the spinal implant 10. As discussed above, suchmovement of the separator 60 serves in expanding the implant 10 byforcing the upper portion 20 and the lower portion 30 apart from oneanother.

The insertion tool 80 includes a handle portion 82 configured to be heldby a surgeon, and an operational portion 84 configured to cooperate withthe separator 60. The operational portion 84 defines an axis Y-Y that isoriented generally transverse to the handle portion 82. As depicted inFIGS. 8 and 9, when the insertion tool 80 is applied to the spinalimplant 10, the axis Y-Y of the operational portion 84 is generallycoaxial with the axis X-X of the spinal implant 10.

As depicted in FIG. 4, operational portion 84 includes a proximate end86 and a distal end 87 opposite from one another. Furthermore, theoperational portion 84 includes a body portion 88, a knob portion 90, anelongated shaft portion 92, and an elongated rod portion 94 moveablewith respect to the shaft portion 92. As depicted in FIG. 4, the knobportion 90 includes the proximal end 86 and extends from the bodyportion 88 towards the proximal end 86, and the shaft portion 92includes the distal end 87 and extends from the body portion 88 towardsthe distal end 87. The rod portion 94 extends from the body portion 88towards the distal end 87 and is extendable beyond the distal end 87.The shaft portion 92 includes an aperture 95 for receiving the rodportion 94 therethrough that extends from the body portion 88 towardsthe distal end 87. Prior to inserting the knob portion 90 into the bodyportion 88, the rod portion 94 is advanced into engagement with thespinal implant 10 either manually or via another tool (not shown).

The shaft portion 92 is partially split along the axis Y-Y, and includesa first arm portion 96 with a first flange 97 and a second arm portion98 with a second flange 99. The first and second flanges 97 and 99 areprovided at the distal end 87 of the operational portion 84. The firstand second arm portions 96 and 98 (and the first and second flanges 97and 99) are biased toward the axis Y-Y, and the first and second flanges97 and 99 are moveable from a disengaged position to an engagedposition.

The rod portion 94 extends from the aperture 95 between the first andsecond arms 96 and 98 towards the distal end 87. Movement of the rodportion 94 within the shaft portion 92 towards the distal end 87 movesthe two flanges 97 and 99 apart from one another. In doing so, the firstand second flanges 97 and 99 can be moved from the disengaged positionto the engaged position. As depicted in FIG. 5, when in the disengagedposition, the first and second flanges 97 and 99 can be received throughthe aperture 48 formed in the proximal wall 40. Thereafter, movement ofthe first and second flanges 97 and 99 from the disengaged position tothe engaged position serves in expanding the flanges 97 and 99 apartfrom one another and into contact with the sides of the aperture 48. Asdepicted in FIG. 6, such contact serves in holding the spinal implant 10on the distal end 87 of the operational portion 84 of the insertion tool80. The rod portion 94 includes an end portion 100 with threads 102provided thereon, and the threads 102 move into engagement with theseparator 60. In doing so, the end portion 100 and threads 102, asdepicted in FIGS. 8 and 9, are received in the threaded aperture 65 inthe trailing portion 62 of the separator 60 and rotated into engagement.As depicted in FIG. 7, with the spinal implant 10 being held by theinsertion tool 80 with the knob portion 90 engaged to the body portion88, the insertion tool 80 can be used to insert the spinal implant 10into the disc space between the two adjacent vertebrae.

With the knob portion 90 engaged to the body portion 88, movement of theknob portion 90 serves in manipulating the rod portion 94. For example,rotation of the knob portion 90 linearly advances the rod portion 94,and movement of the knob portion 90 along axis Y-Y results in movementof the rod portion along axis Y-Y.

Further movement of the knob portion 90 can result in further motion ofthe rod portion 94 along axis Y-Y. Such motion of the rod portion 94exerts pressure against the separator 60, and such pressure applied tothe separator 60 can break the separator 60 free from its attachment tothe remainder of the spinal implant 10. For example, such pressure canbreak the two stems 68 to release the separator 60 from its attachmentto and suspension from the upper portion interior surface 28. Onceseparated from the remainder of the spinal implant 10, the separator 60can be moved by the rod portion 94 (via movement of the knob portion 90)along the upper portion of interior surface 28 and the lower portion ofinterior surface 38 toward the distal end 14. As discussed above, suchmovement forces the upper portion 20 and lower portion 30 away from oneanother, so that the spinal implant 10 can be moved from the unexpandedconfiguration (FIG. 8) to an expanded configuration (FIG. 9).Ultimately, the separator 60 is moved by the rod portion 94 into seatingengagement in the generally concave depression 70 and the notch 56 tomaintain the spinal implant 10 in the expanded configuration.

After the spinal implant 10 has been implanted, moved from theunexpanded position to the expanded position via movement of theseparator 60, and the insertion tool 80 is detached from the spinalimplant 10, the interior cavity C can be packed with fusion promotingmaterials to facilitate its use as a spinal fusion cage. For example,the fusion promoting materials can be inserted through the aperture 48in the proximal wall 40 into the interior cavity C.

As discussed above, the second embodiment of a unitarily formedexpandable spinal implant 110 is depicted in FIGS. 10-13, and the thirdembodiment of a unitarily formed expandable spinal implant 210 isdepicted in FIGS. 14-17. Numerals similar to those used to describe thefeatures of the spinal implant 10 are also used to describe the featuresof the spinal implants 110 and 210. Like the spinal implant 10, thespinal implants 110 and 210 can be moved from an unexpandedconfiguration (FIGS. 12 and 16) to an expanded configuration (FIGS. 13and 17).

The present invention further includes a method of manufacturing theunitarily formed expandable spinal implants 10, 110, and 210 having thestructural features described above using a 3-dimensional printer. Themethod includes forming sequential layers of each of the above-describedcomponents of the unitarily formed expandable spinal implants 10, 110,and 210 by selectively sintering layers of titanium powder, with alaser, to create sequential layers of each component. The titaniumpowder is applied, and successive layers sintered, until each respectivecomplete component, and eventually the complete unitarily formedexpandable spinal implants 10, 110, and 210, configured as disclosedabove, is manufactured. Preferably, the titanium powder is provided by apowder dispensing mechanism, and the laser is controlled by a computer,preprogrammed with CAD data depicting the configuration of each part ofthe unitarily formed expandable spinal implants 10, 110, and 210, asdescribed above. One complete exemplary description of the manufacturingprocess used by the 3-dimensional printer is disclosed in U.S. Pat. No.5,639,070, the contents of which are incorporated herein by reference.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

What is claimed is:
 1. A method of manufacturing a unitarily formedexpandable spinal implant for implantation in a disc space between twoadjacent vertebrae, the method comprising: utilizing a 3-dimensionalprinter to lay down sequential layers of an upper portion having aproximal end and an opposite distal end, the upper portion having anupper portion exterior surface and an upper portion interior surface,the upper portion exterior surface and the upper portion interiorsurface extending from at least adjacent the upper portion proximal endto at least adjacent the upper portion distal end, the upper portionexterior surface being configured to contact one of the two adjacentvertebrae, and at least a portion of the upper portion interior surfaceat least in part declining between the upper portion proximal end andthe upper portion distal end; utilizing the 3-dimensional printer to laydown sequential layers of a lower portion having a proximal end and anopposite distal end, the lower portion having a lower portion exteriorsurface and a lower portion interior surface, the lower portion exteriorsurface and the lower portion interior surface extending from at leastadjacent the lower portion proximal end to at least adjacent the lowerportion distal end, the lower portion exterior surface being configuredto contact the other of the two adjacent vertebrae, and at least aportion of the lower portion interior surface at least in part incliningbetween the lower portion proximal end and the lower portion distal end;utilizing the 3-dimensional printer to lay down sequential layers of aproximal wall having an exterior surface and an interior surface, theproximal wall extending between the upper portion and the lower portion,the proximal wall having a maximum height, and an aperture provided inthe proximal wall between the interior surface and the exterior surfacethereof, the aperture provided in the proximal wall communicating with achamber formed between portions of the upper portion interior surfaceand the lower portion interior surface; utilizing the 3-dimensionalprinter to lay down sequential layers of a first distal wall portion anda second distal wall portion, the first distal wall portion beingattached to the upper portion at the distal end thereof, the seconddistal wall portion being attached to the lower portion at the distalend thereof, the first distal wall portion and the second distal wallportion having a first height less than the maximum height of theproximal wall; and utilizing the 3-dimensional printer to lay downsequential layers of a separator including a leading portion, theseparator being unitarily formed with one of the upper portion interiorsurface, the lower portion interior surface, and the interior surface ofthe proximal wall by at least one point of attachment; wherein theseparator is configured to be separated from the at least one point ofattachment, and be moved along at least a portion of the lower portioninterior surface and at least a portion of the upper portion interiorsurface toward the first distal wall portion and the second distal wallportion to move the upper portion and the lower portion apart from oneanother into an expanded configuration, the first distal wall portionand the second distal wall portion having a second height in theexpanded configuration greater than the maximum height of the proximalwall.
 2. The method of claim 1, wherein titanium powder is used with the3-dimensional printer to manufacture the unitarily formed expandablespinal implant.
 3. The method of claim 1, further comprising utilizingthe 3-dimensional printer to lay down sequential layers of an insertiontool configured to separate the separator from the at least one point ofattachment and move the separator along the portions of the lowerportion interior surface and the upper portion interior surface.
 4. Themethod of claim 1, further comprising utilizing the 3-dimensionalprinter to define at least one opening between the upper portioninterior surface and the upper portion exterior surface.
 5. The methodof claim 1, further comprising utilizing the 3-dimensional printer todefine at least one opening between the lower portion interior surfaceand the lower portion exterior surface.
 6. The method of claim 1,wherein the separator is separably attached to the one of the upperportion interior surface, the lower portion interior surface, and theinterior surface of the proximal wall by at least one point ofattachment.
 7. The method of claim 6, further comprising providing aninsertion tool configured to be inserted through the aperture in theproximal wall, and into contact with the separator to break theseparator free from the at least one point of attachment, and move theseparator toward the first distal wall portion and the second distalwall portion.
 8. The method of claim 7, wherein the separator includesan aperture, and the insertion tool includes a distal end configured tofit into the aperture of the separator.
 9. The method of claim 1,wherein the upper portion interior surface includes a concave portionadjacent the first distal wall portion, and the lower portion interiorsurface includes a concave portion proximate the second distal wallportion.
 10. The method of claim 9, wherein the concave portions of theupper portion interior surface and the lower portion interior surfaceare configured to receive therein portions of the separator, the concaveportions inhibiting further movement of the separator along the lowerportion interior surface and the upper portion interior surface.
 11. Themethod of claim 1, wherein at least a portion of the chamber between theupper portion and the lower portion is configured to receive bone growthmaterial therein.
 12. A method of manufacturing a unitarily formedexpandable spinal implant for implantation in a disc space between twoadjacent vertebrae, the method comprising: utilizing a 3-dimensionalprinter to lay down sequential layers of an upper portion having aproximal end and an opposite distal end, the upper portion having anupper portion exterior surface and an upper portion interior surface,the upper portion exterior surface and the upper portion interiorsurface extending from at least adjacent the upper portion proximal endto at least adjacent the upper portion distal end; utilizing the3-dimensional printer to lay down sequential layers of a lower portionhaving a proximal end and an opposite distal end, the lower portionhaving a lower portion exterior surface and a lower portion interiorsurface, the lower portion exterior surface and the lower portioninterior surface extending from at least adjacent the lower portionproximal end to at least adjacent the lower portion distal end;utilizing the 3-dimensional printer to lay down sequential layers of aproximal wall having an exterior surface and an interior surface, theproximal wall extending between the upper portion and the lower portion,the proximal wall having a maximum height, and an aperture provided inthe proximal wall between the interior surface and the exterior surfacethereof, the aperture provided in the proximal wall communicating with achamber formed between portions of the upper portion interior surfaceand the lower portion interior surface; utilizing the 3-dimensionalprinter to lay down sequential layers of a first distal wall portion anda second distal wall portion, the first distal wall portion beingattached to the upper portion at the distal end thereof, the seconddistal wall portion being attached to the lower portion at the distalend thereof, the first distal wall portion and the second distal wallportion having a first height less than the maximum height of theproximal wall; and utilizing the 3-dimensional printer to lay downsequential layers of a separator including a leading portion, theseparator being unitarily formed with one of the upper portion interiorsurface, the lower portion interior surface, and the interior surface ofthe proximal wall by at least one point of attachment; wherein theseparator is configured to be separated from the at least one point ofattachment, and be moved along at least a portion of the lower portioninterior surface and at least a portion of the upper portion interiorsurface toward the first distal wall portion and the second distal wallportion to move the upper portion and the lower portion apart from oneanother into an expanded configuration, the first distal wall portionand the second distal wall portion having a second height in theexpanded configuration greater than the maximum height of the proximalwall.
 13. The method of claim 12, wherein titanium powder is used withthe 3-dimensional printer to manufacture the unitarily formed expandablespinal implant.
 14. The method of claim 12, wherein the separator isseparably attached to the one of the upper portion interior surface, thelower portion interior surface, and the interior surface of the proximalwall by at least one point of attachment.
 15. The method of claim 14,further comprising providing an insertion tool configured to be insertedthrough the aperture in the proximal wall, and into contact with theseparator to break the separator free from the at least one point ofattachment, and move the separator toward the first distal wall portionand the second distal wall portion.
 16. The method of claim 12, whereinthe upper portion interior surface includes a concave portion adjacentthe first distal wall portion, and the lower portion interior surfaceincludes a concave portion proximate the second distal wall portion. 17.The method of claim 16, wherein the concave portions of the upperportion interior surface and the lower portion interior surface areconfigured to receive therein portions of the separator, the concaveportions inhibiting further movement of the separator along the lowerportion interior surface and the upper portion interior surface.
 18. Amethod of manufacturing a unitarily formed expandable spinal implant forimplantation in a disc space between two adjacent vertebrae, the methodcomprising: utilizing a 3-dimensional printer to lay down sequentiallayers of an upper portion having a proximal end and an opposite distalend, the upper portion having an upper portion exterior surface and anupper portion interior surface, the upper portion exterior surface andthe upper portion interior surface extending from at least adjacent theupper portion proximal end to at least adjacent the upper portion distalend, at least a portion of the upper portion exterior surface beingconfigured to contact one of the two adjacent vertebrae; utilizing the3-dimensional printer to lay down sequential layers of a lower portionhaving a proximal end and an opposite distal end, the lower portionhaving a lower portion exterior surface and a lower portion interiorsurface, the lower portion exterior surface and the lower portioninterior surface extending from at least adjacent the lower portionproximal end to at least adjacent the lower portion distal end, at leasta portion of the lower portion exterior surface being configured tocontact the other of the two adjacent vertebrae; utilizing the3-dimensional printer to lay down sequential layers of a proximal wallhaving an exterior surface and an interior surface, the proximal wallextending between the upper portion and the lower portion, the proximalwall having a maximum height, and an aperture provided in the proximalwall between the interior surface and the exterior surface thereof, theaperture provided in the proximal wall communicating with a chamberformed between portions of the upper portion interior surface and thelower portion interior surface; utilizing the 3-dimensional printer tolay down sequential layers of a separator including a leading portion,the separator being unitarily formed with one of the upper portioninterior surface, the lower portion interior surface, and the interiorsurface of the proximal wall by at least one point of attachment;wherein the separator is configured to be separated from the at leastone point of attachment, and be moved along at least a portion of thelower portion interior surface and at least a portion of the upperportion interior surface toward the first distal wall portion and thesecond distal wall portion to move the upper portion and the lowerportion apart from one another into an expanded configuration.
 19. Themethod of claim 18, wherein the separator is separably attached to theone of the upper portion interior surface, the lower portion interiorsurface, and the interior surface of the proximal wall by at least onepoint of attachment.
 20. The method of claim 18, wherein the upperportion interior surface includes a concave portion adjacent the distalend of the upper portion, and the lower portion interior surfaceincludes a concave portion proximate the distal end of the lowerportion, and wherein the concave portions of the upper portion interiorsurface and the lower portion interior surface are configured to receivetherein portions of the separator, the concave portions inhibitingfurther movement of the separator along the lower portion interiorsurface and the upper portion interior surface.